1) Field of the Invention
The present invention relates to a bar-code reader and a method of reading a bar code.
2) Description of the Related Art
Products are managed by providing a bar code to the product and identifying the product by reading this bar code optically. Since the bar code labels can be prepared at a low cost by printing etc., by using such bar code labels, it is possible to reduce the management cost substantially.
The bar-code labels attached to the products are read using a bar code reader. Such a bar code reader generally includes an optical system like a laser reader, a charged coupled device (CCD) camera etc. The bar code reader receives light that is reflected from a bar code label, determines a pattern of the white lines and the black lines in the bar code from the optical power of the light reflected, and then decodes this pattern to obtain character data that is a pattern of numerals and characters.
However, since scan data includes information even before and after the bar-code array, if the whole of the scan data is subjected to decoding, load during processing increases considerably. In other words, if a bar-code array can be extracted accurately from the scan data, load during processing can be decreased.
To extract the bar-code array from the scan data, one approach is to specify a starting position of a bar code in the scan data. This approach has been disclosed in Japanese Patent Application Laid-open Publication No. 2000-507727.
However, sometimes the scan data includes more than one areas with a high probability of being bar codes. Particularly, when there is a pattern like character string or mesh around the bar code, an area with a high probability that this character string or mesh pattern is a bar code, i.e. a bar-code candidate area, is extracted.
In conventional bar-code readers, when there area a plurality of such bar-code candidate areas, all the areas are decoded and a judgment of whether a bar-code candidate area is a bar code or not is made. However, this approach exerts considerable load on bar-code decoding, which results in decline in efficiency of reading.